by Jake Meyer

While driving in holiday traffic you may be cut-off by a motorist who erratically enters your lane without using a turn signal or you may need to suddenly slam on your brakes to avoid another motorist who brakes with no warning.  And you may find yourself honking your horn and shouting "where did you learn to drive?"  But what if bad drivers didn’t learn to drive like bad drivers, but instead were born bad drivers? 

A recent study by neurologist Dr. Steven Cramer at University of California Irvine suggests that bad driving may be in part genetically based, finding that drivers with a certain gene variant performed 20 percent worse on a driving test than drivers without the gene variant. The study looked at the gene associated with the production of a protein called brain-derived neurotrophic factor (BDNF).  BDNF supports communication among brain cells and keeps them functioning optimally.  Previous studies have shown that people with the BDNF gene variant, when engaged in a task, have a smaller portion of their brain active than those with a normal BDNF gene variant. The study put 29 people in a driving simulator – 22 without the gene variant and 7 with the gene variant – and had them drive 15 laps on track with difficult turns and curves.  Four days later, the participant returned to drive the same 15 laps.  The participants with the gene variant did worse on both tests and also remembered less of the track the second time. 

Dr. Cramer has said that "I wonder if the accident rate is higher for drivers with the variant."  The results of the simulator study suggest that the rate very well could be higher.  While a commercial genetic test doesn't currently exist, such a test wouldn't be too difficult to offer.  If the rate of accidents was significantly higher among drivers with the BDNF gene variant, then car insurance companies would be very interested in knowing this genetic information so that they could raise the rates for these at-risk drivers.  The Genetic Information Nondiscrimination Act (GINA) prohibits the use of genetic information for discriminatory purposes in employment and healthcare, but a similar protection doesn't exist for car insurance.

Or what if a state decides that these BDNF drivers are such a risk that they should be kept off the roads?  Should drivers have to pass both a drivers test and a genetic test?  Such a test in America would have the effect of creating a class of "drivers" and "riders," as 30 percent of Americans have the BDNF gene variant.  Although such a scenario may be a bit outlandish in an automobile centric country like America, it does highlight the sorts of risks of that we need to be concerned about as modern science discovers more genetic links.